Pneumatic hammer



Sqz 15, 1925 I v 1,553,598

o. coouv I PNEUMATIC HAMMER Filed April 28. 1922 2 Sheets-Sheet 1 n-s l entm is: D C0023;

- Gun/meg Patented Sept. 15, 1925. v

PATENT. OFFICE.

. FREDERICK n. COOLEY, on DETROIT, MICHIGANQ v PNEUMATIC HAMMER.

Application filed April 28, 1922. SerialNo. 557,151.

ToaZZ whom it may concern: i Be it known that LFnnnnniok D. Coo- EN, citizen of the United States, residingat Detroit, county of Wayne, State of Michigan, have invented a certain new and useful lin provement in Pneumatic Hammers, and de. c-lare the following to be a full, clear, and exact description of the same, such as will enable others skilled in the art to which it pertains to make and use the same, reference being had to the accompanying drawings, which form a part of this specification;

My invention relates'to automatic hammers and an object of my improvements is to provide a portable self-contained tool that shall be effective and convenient as an improved mechanical hammer.

I secure this object in .the device illustrated in the accompanyingv drawings, in

whichi Figure 1 is a side elevation of a portable tool involving my invention. I

Fig. 2 is a plan view of the same partly v in section. v

Fig. 3 is a detailed end elevation looking from the rightof Fig. 1. I

4 Fig. l is a section on the line 4 4, Fig. 2, to an enlarged scale. i f

Fig. 5 is a section on the line 5-5, Fig. 2, to an enla-rged scale. 7 H

Fig. 6 is a section on the line 6-6, Fig. 2

Fig. 7 is a detailed section to an enlarged scale, partly broken away to shorten the figure, the part at the left of the line indicating the break, being in asomewhat'different plane to show the pump valve construction.

a, a, (4 indicates the casing, as a whole, of a mechanical hammer conveniently portable by means of a handle a a is a cylindrical portion of said casing of reduced diameter, having a co-axial aperture a in its end for receiving the cutting tool upon which the hammer is designed to act. a is a part of the casing a in which the mechanism for applying the power is enclosed. a is a co-axial portion of the casing of the same diameter as a, and forming an extension of the same, in which an electric motor is enclosed. a is a co -axial part of the casing a in which the commutator of the electric motor is contained and a is the handle which is joined to the p rtion c of said. casing.

a (Fig. 7) is a partition extending transversely across the interior of .theca'sing a between the portions .2 and a of said casing.

b is a cylinder contained within the portion a of the casing a, co-axial with said casing, having thepartition a closing one end, extending forward and having its other end open. i

0 is a reciprocating plunger of cylindrical form at its ends fitting at '0? into the bore a of the casing a and at '0 fitting into the bore of the cylinder 0. The plunger 0 iscut away at opposite sides as indicated at 0*. cl, cl are friction rollers extending laterally from the cut-away portions of the plunger 0 upon opposite sides thereof.

e, e are shafts parallel to the axis of the casing a and plunger 0 located upon opposite sides of' said plunger. 6 e are cams upon the shafts e, 6; These cams are provided with thrust bearings 6 e at their .forward ends The cams e are adapted to engage the rollers cl, d'toretract the plunger 0 and force it into the cylinder I). Said cams are, therefore, provided with a face adapted to gradually act upon the rollers d, cl as the shafts e, e are turnedand are provided with steep (in this case, perpendicular) faces 6 to permit. the quick forwardmo-vement of the Plunger Q todeliver the hammer blow. e earegear wheelsupon the ends of the shafts e, e remote'from the thrust bearings 6 e f is an electric motor, the armature of which is secured upon a shaft f and is also conventional brushes, not shown. 7 is a switch device by which'the current may be turned on to the motor 7 or the circuit through said motor broken. f is a gear wheel upon the inner end of the shaft 7? of the motor This gear wheel has its teeth engaging the gear wheels e 6 on opposite sides.

g is a small compressor'communicating by means of a passage 9 with a non-return valve therein, with a cylinder 1) insideof the plunger 0. The compressor 9 is provided with a connecting rod (Fig. 6) which is'eccentrically pivotedto the face of a gear wheel 9* atg.

m, 00, (Fig. 4) are friction rollers pivotedv to and. extending latera ly from the plunger c at points ninety degrees from the friction rollers (Z, d. The friction rollers 00, 00 reciprocate between guides y, y.

The casing a, a with its handle a has the conventional form of a pneumatic hammer. The mode of operation Orr-.116 above-v described device is as follows: An air pressure is maintained-by the 00111- pressor g in the cylinder 6 between the closed end of said cylinder and 'the end c of the plunger 0.

To set the apparatus in motion the circuit through the electric motor is, completed by manipulating theswitch f. This energizes the motor whic revolves the haa rand consequently the shafts e, 6 through the gear wheels f and a 6". The rotation of the shafts e, e rotate the, cams e 3 which act to .letract the plunger'c againstthepi es sure of the air in thecylinder b until the,- steep, faces 0 of said cams'pass. the/rollers 03 when the plunger c is forced forward by the pressure of. the air in the cylind'enb and 'deliVerst-he hammer blow, The rotation of the gear wheel a actuatesthe coin.- pressor .g to maintain a pressure of air in the cylinder .5, a i h i It will be observed that this device is entirely self-contained. The .air chamber is entirely'enclosed and centaiiied w'ithin the [casing u and the contained "air under pressure is permanent, the compressor only s rving to supply any leakage that may occur. It constitutes a 'tool that is easily transported and: handled andmay be used v'vherjever a source of electrical power is available. i i

' lVhat-I claim is:

1. In an apparatus ofthe kind described, the combination of portable casing, a re} ciprocating part, resilient .means continuously acting to force Said reciprocating part rorwara w deliverthehammer stroke,

casing, 21. refliprocating part, a resilient means continuously acting to force said reciprocating part forward to deliver the hammer stroke, ,aTmotor' carriedby said fra e having'a rotating part axially line with said reciprocating part, cams on opposite" sides of said reciprocating 'I'Jart adapted to be rotated about the axes parallel to the motion of=said reciprocatingpart and adapted to engage said rotatingpart to retract and release the same, a'gear wheel uponeachof said cams and a gear wheel upon the rotating part of said 'motor located between the gear wheels connected with said cams and'engaging the same.

3.In'"ahammer, the combination of a casing adapted to .be c arried in thehands ofa workman, said casing including a cylinder closed at one end,a plunger fitting and adapted to reciprocate in said cylinder, a motor inv said casing carried thereby,

'means in said casing and carried-thereby actuated by saidmotor for maintaining air under pressure between said plunger and the closed end of said casing to force said plunger forward to deliver the hammer blow, said meter being adapted to retract said plunger and release these-me, for the purpose described.

In testimony whereof, I signthis specification.

FREDERICK 000111 155. 

